The technology of the present disclosure relates to an exercise support apparatus and an exercise support method mounted and used on a human body of an elderly person or the like who mainly wants assistance or care and configured to physically and mentally support exercise of a human body that includes a walking motion.
The rate of aging in Japan (a rate occupied by the elderly population of 65 years or more with respect to total population) reached 23.1% in 2010 and is expected to arrive at 30% in 2025. When a rate occupied by the elderly population rapidly increases as described above, realization of a society in which the elderly can live their lives as healthily and actively as possible rather than in a primary nursing care state, and even in a primary nursing care state can prevent deterioration as much as possible and live their independent lives becomes urgent.
According to arrival of the aging society, in an elderly care facility or a family including elderly members, requirements of a mechatronics instrument for the purpose of support of mind and body of the elderly is increased. Most of all, there is a high demand for a machine configured to perform physical assistance such as an autonomous walking assistance device or a power assist suit.
One of important points in development of a mechatronics instrument for assistance and care is to maintain and accelerate activities of the elderly as much as possible without unnecessary interference. When the activities of the elderly are excessively undertaken by a machine due to reduced physical fitness of the elderly, the physical fitness of the elderly is further weakened and circumstances also deteriorate (disuse syndrome). The power assist suit is an apparatus configured to apply an artificial force as an auxiliary force in addition to a force generated by a human's muscle. Accordingly, the apparatus is an exemplary instrument in that the elderly person's own activity is maintained while supplementing a decrease in the physical fitness of the elderly person.
Assistance with the force for the elderly is becoming technically possible. However, in recent times, a proliferation rate of the power assist suit has not been very high. This may be considered as being caused by the following reasons.
(1) Attachment and detachment of the apparatus is not easy. In addition, long term use may cause discomfort.
(2) Price is high, and cost effectiveness is not good.
(3) Appearance upon mounting is unnatural and awkward, and thus external competitiveness in market is reduced.
(4) A wide range of exercise support of a user from sitting to walking may not be performed.
(5) The weight of the instrument is applied to the user, and only the awkward support is merely performed. In addition, a lateral reverse moment may easily occur due to a support force.
(6) Dependence on a body size of the user is high.
(7) A working time is short.
For example, a force control type power assist suit configured to apply a drive force to a joint based on an output from a myoelectric sensor and a result of phase estimation of an exercise has been receiving attention in recent times (for example, see Kawamoto H., Lee S., Kanbe S., Sankai Y.: “Power Assist Method for HAL-3 using EMG-based Feedback Controller”, Proc. of Int'l Conf. on Systems, Man and Cybernetics (SMC2003), pp. 1648-1653, 2003). However, according to the power assist suit, at least nine myoelectric sensors should be attached to one leg, and thus mounting labor is largely consumed. In addition, the myoelectric sensor may be separated from the skin due to changes over time or sweat. When adhesion between the myoelectric sensor and the skin is broken, an output value of the myoelectric sensor may become unstable, the power assist suit may malfunction, or an inappropriate force may be applied to a human body wearing the suit. Such insufficiency has interfered with proliferation of the power assist suit.
On the other hand, a human body support apparatus not using the myoelectric sensor has also been proposed (for example, see J. Ghan. R. Steger, Kazerooni, H, “Control and System Identification for the Berkeley Lower Extremity Exoskeleton”, Advanced Robotics, Volume 20, Number 9, pp. 989-1014, Number 9, 2006). The human body support apparatus is configured to sense movement of a user's joint and apply a force to the joint to support the movement. However, since the human body support apparatus is a structure mounted on the outside of the body, dependence on a size in a widthwise direction of a user's body remains, and the apparatus may be increased in size.
In addition, a boarding type walk support apparatus mounted on the inside of both legs of a user has also been proposed (for example, see Japanese Patent No. 4641225). However, since a knee region of the walk support apparatus largely protrudes from the body, a problem with external appearance occurs. In addition, since an arch-shaped structure is provided under the crotch, the user may not sit on a seat while mounting the walk support apparatus. That is, the walk support apparatus may not perform a wide range of exercise support from sitting to walking.
Further, a walk assist system configured to perform hip joint support according to a phase of walking has been proposed (for example, see Japanese Patent Application Laid-open No. 2011-62463). The walk assist system is constituted by a handstand pendulum type moving body gripped by a user, and a walk support apparatus configured to support an exercise of the user's leg. Then, the handstand pendulum type moving body controls motion of a base body when a user grips and movement based on a target moving speed and the walk support apparatus transmits a force to the user based on motion of the body of a user's leg and the target moving speed such that the target moving speed has a predetermined speed relation between the handstand pendulum type moving body and the walk support apparatus. However, the walk assist system is designed to perform a slight degree of assistance of a swing leg, but may not perform practical force support such as lifting of a weight needed upon ascent of stairs, and raising of the swing leg.